The present invention relates to the field of materials management, and more particularly to systems designed for containing, transferring, delivering and dispensing various materials. The present invention is more particularly directed to a refillable material transfer system having a constant-pressure portable pressurization sub-system.
Prior known material management systems have encountered difficulty transferring from a containment vessel certain thick, viscous fluids, liquids and other types of materials that may resist pumping and that can be damaging to pumping apparatus. As used herein, a fluid is a substance that is capable of flowing and that changes its shape at a steady rate when acted upon by a force tending to change its shape. Certain materials, while normally not considered to be fluids, also can be made to flow under certain conditions, for example, soft solids and semi-solids. Vast quantities of fluids are used in transportation, manufacturing, farming, mining, and industry. Thick fluids, viscous fluids, semi-solid fluids, visco-elastic products, pastes, gels and other fluid materials that are not easy to dispense from fluid sources (for example, pressure vessels, open containers, supply lines, etc.) comprise a sizable portion of the fluids utilized. These fluids include thick and/or viscous chemicals and other such materials, for example, lubricating greases, adhesives, sealants and mastics. In the food processing industry, cheeses, creams, food pastes and the like must be moved from point to point without degrading the food's quality and freshness. In the manufacture and use of industrial chemicals and pharmaceutical products, hard to move fluids that are thick and/or viscous are commonly used. The ability to transport these materials from one place to another, for example, from a container to a manufacturing or processing site, and in a manner that protects the quality of the material, is of vital importance.
Transporting, handling, delivering and dispensing thick and/or viscous materials presents a challenge because these materials resist flowing and are not easily dispensed or moved out of their containers. Prior known methods of delivering viscous fluids have concentrated on establishing and maintaining a fluid tight seal between pushing pistons or follower plates, and side walls of the containers of viscous materials. These devices, however, are highly susceptible to disruption if the sidewalls of the viscous material container become out-of-round or dented. Moreover, some systems require high precision in all its parts, and require relatively bulky and expensive equipment. Furthermore, most known systems for material transport of fluids require the use of an external pump with a container having a follower plate. Moreover, the pump and follower plate are connected or otherwise coupled so as to increase the expense and mechanical sophistication of such material transfer systems.
Heretofore known vessels and containers were basic moderate-high-pressure vessels having characteristics that were deficient in transferring difficult to move materials. For example, such vessels often were relatively heavy, mild steel, converted air receivers. Other such vessels were merely thin-walled, special steel alloy, converted propane tanks. Accordingly, the vessels were manufactured under DOT regulations, and therefore required relatively frequent re-certification. Such containers also were susceptible to internal rusting, and often were closed, and therefore difficult to clean. Furthermore, the containers were not bimodal (for liquids and/or thick fluids). In addition, past container internals consisted of only one internal subsystem, a follower device that had a single function, to prevent high-pressure gas bypassing. These follower devices were difficult to fabricate, relatively expensive, rust-prone and could not wipe the vessel walls, even if desired by the user. Many such systems contained heavy “ballast” that was not modifiable after fabrication and were easily canted (tipped) if container was placed on its side.
One disclosed reusable viscous material dispensing apparatus system includes a follower boat having a lower hull portion that is weighted with ballast. The diameter of the boat is smaller than the inner diameter of the cylinder, such that the boat floats in a cylinder filled with viscous materials, such as thick lubricating greases. In use of the system, the cylinder is filled with a viscous material through its ingress and egress opening. By applying compressed gas to the boat from above, the boat attempts to force the viscous material out of the container through a common ingress and egress opening, until the bottom of the boat seats on and blocks the opening. However, the disclosed container is configured as a vertical, closed, pressure vessel that may be difficult to clean. Moreover, the disclosed boat is a single-function (prevents gas bypass), heavy, difficult to manufacture apparatus.
Accordingly, there is a need for, and what was heretofore unavailable, a refillable material transfer system having a portable constant-pressure compressed gas subsystem that can move highly viscous fluids from a vessel to a point of use. Similarly, there is a need for a material transfer system that will dispense only the required amount of material without waste, which is especially important when chemicals are not easily handled and cannot be manually removed easily or safely from the vessel. Preferably, such a material transfer system would reduce or eliminate costs and expenses attendant to using drums, kegs and pails, as well as the waste of material associated with most existing systems. Because certain chemicals are sensitive to contamination of one form or another, there is a further need for a material transfer system that is sealed, protects product quality, allows sampling without opening the container to contamination and permits proper attribution of product quality problems to either the supplier or the user. Likewise, there is need for a refillable material transfer system that uses low cost components and provides a non-mechanical (no moving parts), non-pulsating solution for dispensing and transferring thick fluids and other such materials. The present invention satisfies these and other needs.